3.1- Exchange surfaces Flashcards
(48 cards)
Do small animals have a large or small surface area to volume ratio?
Large
How do you calculate surface area to volume ratio?
Divide the surface area by the volume
Why do single-celled organisms normally not need specialist transport systems?
The substances can diffuse directly into or out of the cell across the membrane
The diffusion rate is quick because of the small distances
Why do multicellular organisms normally need specialist transport systems?
There’s a large diffusion distance
They have a low surface area to volume ratio
They have a high metabolic rate, so use up oxygen in glucose faster
What three features improve the efficiency of specialised exchange surfaces?
Large surface area
Thin
Good blood supply / ventilation
How are root hair cells adapted for efficient exchange?
The cells and plant roots grow into long have which stick out into the soil and gives the roots and large surface area which increases the rate of absorption of water and mineral ions
How are alveoli specially adapted for efficient exchange?
Each alveolus is made from a single layer of thin flat cells which decrease the diffusion distance
The large capillary network surrounding each alveolus helps maintain concentration gradient
Name 4 substances an organism needs to exchange with its environment.
Oxygen, glucose, carbon dioxide, urea
How are fish gills specially adapted for efficient exchange?
They contain a large network of capillaries and a well ventilated which maintains a high concentration gradient
What are the exchange organs in mammals?
Lungs
Describe the route that air takes to get to your lungs.
Trachea splits into two bronchi
Each bronchus then branches off into bronchioles
The bronchioles go to the alveoli
What is the function of goblet cells?
Goblet cells secrete mucus which traps microorganisms and dust particles, stopping them from reaching the alveoli
What is the function of cilia?
Cilia move mucus upwards away from the alveoli towards the throat where it is swallowed to prevent lung infection
What is the function of elastic fibres?
Elastic fibres help the process of breathing out.
On inhalation, the fibres are stretched and then recoil during exhalation
What is the function of Smooth muscle?
Smooth muscle Lines the walls of the trachea, bronchi and bronchioles
It allows there diameter be to be controlled so that during exercise, the tubes are wider
What is the function of rings of cartilage in the trachea and bronchi?
Rings of cartilage stop the trachea and bronchi collapsing when you breathe in and the pressure drops
Does the trachea contain cartilage, smooth muscle, elastic fibres, goblet cells and epithelium?
Cartilage: Large c shaped pieces Smooth muscle: Yes Elastic fibre: Yes Goblet cells: Yes Epithelium: Ciliated
Does the Bronchi contain cartilage, smooth muscle, elastic fibres, goblet cells and epithelium?
Cartilage: smaller pieces than tranchea Smooth muscle: Yes Elastic fibre: Yes Goblet cells: Yes Epithelium: Ciliated
Does the Larger Bronchiole contain cartilage, smooth muscle, elastic fibres, goblet cells and epithelium?
Cartilage: No Smooth muscle: Yes Elastic fibre: Yes Goblet cells: Yes Epithelium: Ciliated
Does the Smaller Bronchiole contain cartilage, smooth muscle, elastic fibres, goblet cells and epithelium?
Cartilage: No Smooth muscle: Yes Elastic fibre: Yes Goblet cells: Yes Epithelium: Ciliated
Does the Smallest Bronchiole contain cartilage, smooth muscle, elastic fibres, goblet cells and epithelium?
Cartilage: No Smooth muscle: No Elastic fibre: Yes Goblet cells: No Epithelium: No cilia
Does the Alveoli contain cartilage, smooth muscle, elastic fibres, goblet cells and epithelium?
Cartilage: No Smooth muscle: No Elastic fibre: Yes Goblet cells: No Epithelium: No cilia
Where is cartilage found in the mammalian gas exchange system?
Trachea and bronchi
Where is smooth muscle found in the mammalian gas exchange system?
Trachea
Bronchi
Large bronchiole
Smaller bronchiole
